Beverage making systems are known where a predetermined amount of a beverage making ingredient, such as ground, freeze dried, or instant coffee, is held in a container or capsule, with or without filtration means, and then placed into a beverage making apparatus. The apparatus then introduces water into the container, where it dissolves, extracts, emulsifies, or dilutes the ingredient(s) to form a beverage. In a typical example, heated water is injected into a container having ground roast coffee in a filter cartridge which infuses the water to form brewed coffee. The beverage exits the container chamber e.g. by flowing through an opening or perforation in the container.
Various beverage making systems and containers therefor are shown in U.S. Pat. No. 5,325,765 (Sylvan et al); U.S. Pat. No. 5,840,189 (Sylvan et al); U.S. Pat. No. 6,142,063 (Beaulieu et al); U.S. Pat. No. 7,318,372 (Cooke); U.S. Pat. No. 6,698,333 (Halliday et al); U.S. Pat. No. 7,418,899 (Halliday et al); and EP-A-0821906 (Sara Lee), EP-A-0512468 (Nestle), EP-A-0468079 (Nestle), WO 94/01344 (Nestle), EP-A-0272922 (Kenco), and EP-A-0179641 (Mars) and WO 02/19875 (Mars), the entire contents of all of which are hereby incorporated herein by reference.
Disposable chambered articles or containers (sometimes referred to as cups or capsules) are used in beverage making systems for steeping, infusing, brewing, diluting, emulsifying, extracting or otherwise contacting liquids such as water with organic material such as coffee to impart flavor, aroma, nutrients or other physiologically active agents are known. These liquids may be hot, cold or ambient temperatures. For example, beverage making systems and filter cartridges such as the Keurig™ cup disposable single serve beverage filter cartridge (commercially available from Keurig, Incorporated, Wakefield, Mass., USA and described and disclosed in incorporated U.S. Pat. Nos. 5,325,765 and 5,840,189 (Sylvan et al)) provide a convenient method to make a cup of a brewed hot beverage and provide a means to offer a wide selection of e.g. coffees and cocoa drinks. A variety of such containers and cartridges are used in beverage brewing machines such as those described above. Beverage cartridges are typically made of a filter element held inside a pierceable base and/or lid. These beverage making systems and containers such as the Keurig cup have been commercially successful however certain disadvantages have led to various attempts for improvements.
Beverage filter cartridges like the Keurig cup comprise a yieldably pierceable cup-shaped container which is otherwise impermeable to water and atmospheric oxygen. These containers may be made by thermoforming sheet or injection molding monolayer or multilayer polymeric resins to form relatively rigid plastic containers or capsules. A container may be internally divided into a plurality of chambers e.g. by filter means such as cone-shaped paper filter into first and second chambers. A dry beverage making ingredient, e.g., roasted ground coffee, is separated from the second chamber by storage in the first chamber, and the container is closed by a yieldably pierceable lid comprising e.g. a laminate of metallic foil and heat sealable plastic. This lid is also otherwise impermeable to water and atmospheric oxygen.
During beverage making, the lid and container bottom are pierced from opposite directions, by tubular inlet and outlet tubes, respectively. The inlet tube introduces heated liquid into the first chamber for infusion with the beverage ingredient(s), and the resulting brewed beverage passes through the filter into a second chamber from which it exits through the outlet tube and into a drinking cup.
The beverage filter cartridges made in accordance with the foregoing Keurig patents have been commercially successful, notwithstanding certain problems and disadvantages relating to their use that have persisted since their introduction.
For example, the base of the container is thick, compared to the lid, with a resultant higher resistance to piercing. Furthermore due to the nature of the thermoforming process the container base is made from a sheet having a relatively uniform thickness and the thermoformed base bottom cannot easily be thinned without also thinning the base sidewall which adversely reduces the rigidity and strength of the base causing a tendency for the sidewall to buckle inward during the piercing process. Also, as the outlet tube is pressed against the base bottom for piercing to permit exit of brewed coffee, a similar buckling may occur. These distortions of the container disadvantageously can result in leakage proximate the outlet tube causing the liquid to spray or coat parts of the apparatus or otherwise remain or locate to undesirable places rather than travel along the desired path to the inside of the drinking cup. This leakage may produce customer dissatisfaction due to loss of product, as well as require additional maintenance to avoid unsanitary conditions or further equipment malfunction.
To ameliorate the difficulty in piercing the base, beverage makers have been equipped with wear resistant, metal outlet tubes that can be sharpened as needed to effectively pierce the container bottoms. These tubes are expensive and may require periodic sharpening.
Another problem associated with distortion of the base by the piercing operation is that some brewed beverage may remain in the second chamber unable to exit due to the distortion proximate the outlet tube pierced opening causing an area within the base to be below the outlet tube opening.
One attempt to address problems associated with piercing the container bottom has been to redesign the container and relocate the outlet tube so that it travels parallel to the inlet tube and also pierces the top of the container which is typically made of thinner lid stock film. This attempt to resolve the problem is further described in U.S. Pat. No. 6,607,762 (Lazaris et al) which is assigned to Keurig. This attempt suffers from the need to provide not only different containers or cartridges, but also a different beverage making apparatus since the outlet tubes must be introduced from a position that is located 180° from the present apparatus location. Thus existing beverage brewers would need to be replaced. Also, there are additional complications attendant to the brewing process since the distribution of ingredient and flow of the liquid are not as easily controlled to yield a uniform extraction from e.g. ground coffee. It is believed that this system while addressing the piercing problem would tend to produce a channelling effect in transfer of the hot water across the coffee resulting in a need for containers made from more material, or which use additional coffee or a longer residence time to produce an equivalent amount of brewed coffee. Additionally the exit tube would require a motive force in opposition to gravity to cause the brewed liquid to exit which is believed to lead to additional expense to create a positive or negative pressure sufficient to effect transport or alternatively necessitates use of additional water to displace the requisite amount of brewed coffee thereby creating a waste of water and additional disposal concerns and weight.
As previously mentioned the container base needs to have sufficient rigidity to avoid buckling induced leaking caused by a puncturing operation during which the outlet tube is inserted. This tendency of the container side wall to buckle under the force exerted by the outlet tube as it pierces or attempts to pierce the container bottom sometimes results in a failure of the outlet tube to achieve the desired penetration, thereby causing a malfunction in the brewing process which prevents delivery of some or all of the brewed beverage to the underlying drinking cup. As previously mentioned, buckling of the container side wall can also distort the punctured opening in the container bottom, thereby disrupting a continuous seal about the tube perimeter which may result in leakage of the brewed beverage.
Other known problems include reliably sealing the flange or rim of the filter component to the interior side wall of the container, as well as in centrally securing the bottom of the filter component to the container bottom. Failure to achieve a proper flange seal can cause the unsealed portion of the filter to collapse under pressure from introduction of the liquid, resulting in the brewed beverage being contaminated by beverage ingredient particles such as coffee grounds from the collapsed filter. Contamination of the beverage may also happen if the filter bottom is not properly located and secured, resulting in the filter being punctured by the outlet probe as it projects upwardly through the container bottom. Contamination also may occur by bursting of a filter element due to the pressure from the heated liquid being infused with the beverage ingredient(s).
Another problem arises from heat sealing the upper rim of the filter at or closely adjacent to the upper rim of the container side wall. This increases the unoccupied head space between the outside of the filter and the surrounding container wall, and also limits the maximum amount of beverage medium that can be stored in the cartridge to that which can be contained within the filter. In some cases, this can compromise the “strength” or extent of extraction of a resulting brewed beverage. Beverage strength can be increased by filling the filter to its maximum capacity, but this can result in errant granules of the beverage medium spilling onto the container rim. This in turn can disrupt the integrity of the seal between the cover and the container rim.
Thus, there needs to be sufficient rigidity to hold and brew the coffee without bursting the container or causing leaking and sufficient rigidity and flexibility to provide a good alignment between the filter and lid stock at the base top flange and good alignment with the inlet and outlet tube perimeters sufficient to permit the flow into and out of the container without undesirable leakage of either liquid or particles such as coffee grounds into the drink. One approach to provide a material that is more easily pierced is to thin the wall of the container however this tends to undesirably decrease rigidity of the container and increase flexibility. To counteract increased flexibility and increase desirable rigidity another approach has been to reconfigure the geometry of the container such as described in U.S. Pat. No. 6,645,537 (Sweeney et al) assigned to Keurig. The Sweeney patent attempts to improve strength and rigidity by providing a fluted geometry. Such fluting may also introduce manufacturing complications by causing thinning of the barrier layers and materials within the container walls which assist the container in preventing or diminishing the permeability thereof to gases such as oxygen which have a deleterious effect on ingredients. In addition, production of fluted containers may reduce production speeds.
Thus, there are several known drawbacks including difficulties associated with piercing or puncturing the container base, lack of rigidity or excessive flexibility in the base and the amount of packaging material required to produce a functional container. There is a desire to provide a container which may easily be pierced by hollow tubes to permit entrance and/or egress of liquids to and from the container during the beverage making process.
There is a continuing need for an improved beverage container including improved filter cartridges that lessen the above-noted problems and disadvantages.
Among the objectives of the present invention it is desirable to minimize material consumption for not only economic reasons, but also for conservation of resources, and to minimize the amount of material to be disposed into landfills or by other means. A container composition that reduces the amount of material required for a functional container would provide a benefit to the product. Containers such as a Keurig cup or cartridge require tight size tolerances with a small range of variation to maintain acceptable levels of performance and these tight tolerances lead to waste in thermoforming operations.
Another object of the present invention is a strengthening of the container side wall to thereby resist buckling when the container bottom is punctured by the outlet tube of the brewer.
Another object of the present invention is to provide a cup which is easy to puncture through the base without deleteriously affecting other properties
A further object of the present invention is to strengthen the container side wall to resist buckling when the container bottom is punctured by the outlet tube of the brewer.
These and other advantages of the invention will be apparent from the description below. It is not necessary that all embodiments of the invention meet all of the objects. It is sufficient that the invention may advantageously be employed. the above advantages singly or in various combinations may be beneficially achieved in various embodiments of the invention.